This invention relates to vehicle height adjusting devices and, particularly, to improvements in vehicle height adjusting devices of the type consisting of a hydraulic damper having a tubular main body and a piston rod slidably projecting from one end of the main body, and an air spring unit having a resilient tubular wall member. The wall member has an inner wall portion and an outer wall portion which are closed at one end by a rolling wall portion formed of the inner and outer wall portions on relative reciprocation therebetween. The inner wall portion is sealingly connected to and surrounds the main body of the hydraulic damper, and the outer wall portion is sealingly connected to the piston rod at the projecting end portion thereof.
The air spring unit is supplied with pressurized air or gas from an external source, and by changing the presence of air or gas supplied to the air spring unit, the overall length of the device can be adjusted.
Usually, a cap member formed of a rigid material is secured to or is sealingly and rotatably mounted on the projecting end portion of the piston rod, and the outer wall portion of the air spring unit is secured to the outer circumference of the cap member.
A fitting for connecting the air spring unit with the source of air or gas under pressure has usually been provided on the cap member, and a conduit connected to the fitting extends generally in a radially outward direction with respect to the longitudinal axis of the device.
When the vehicle height adjusting device of the aforementioned type is mounted on a vehicle, there are problems in the arrangement and the mounting of the conduit, particularly, when the device is utilized on a steerable wheel wherein the main body of the hydraulic damper and the air spring unit are rotatable with respect to the piston rod which is secured to the chasis of the vehicle and, particularly when an additional coil spring is provided between the main body and the projecting end portion of the hydraulic damper for affording an additional spring force, wherein the additional spring surrounds a substantial length of the air spring unit, thus interfering with the conduit.